I need help. I want to know that which version is higher between 4.0.22 and 4.0.4

I want to drop constraints like foreign key but i cant. The query runs successfully but constraint cant be removed. command(show create table tablename) doesnt display internal generated id of foreign key.
I am using phpmyadmin 2.6.1 is there any way in that we can remove it with user interface except SQL statement.
Please help me out.
I am using MySQL version 4.0.4
Please give me information about diff. versions.